The value of high levels of healthcare spending and utilization in the United States is frequently questioned. Using Medicare claims data, Dartmouth Atlas Project researchers identify significant geographic variation in overall spending and use of discretionary and expensive services though patients in higher spending regions do not live longer or report greater overall satisfaction with care received. While more intensive healthcare utilization may not extend patients' lives, there may be important and currently unappreciated consequences of additional treatments for multiple dimensions of patient well-being, including functional status and productive engagement (e.g., working for pay, volunteering, and providing unpaid care to family members). This study assesses the effect of elective surgery to treat four common chronic conditions (arthritis, back pain, cataracts and heart disease) on health and disability outcomes related to quality of life including mobility and depression, and economic outcomes including paid and unpaid work. Longitudinal survey data from the Health and Retirement Study linked to respondents' Medicare claims and national Medicare data will facilitate a difference-in-differences approach to estimating a causal effect of surgery by comparing recipients to non-recipients over time. Geographic variation in practice patterns will allow comparisons of patients receiving surgery at different levels of disease severity. The results of this study will facilitate evidence-based policymaking by the Centers for Medicare and Medicaid Services and other payers, and make timely methodological contributions to the growing field of cost- effectiveness research. Patients, their families, and employers will be the ultimate beneficiaries of these findings as providers and payers can account for the effectiveness of healthcare interventions in preserving typically unmeasured aspects of health and productive engagement. This research will provide important information to policymakers implementing the Affordable Care Act and considering further changes to the Medicare program to address rising healthcare costs and the rapid growth of the over-65 population. Beyond the scientific aims, this career development award will provide training in gerontology, medicine, and public health for a PhD-trained health economist. The skills obtained during the training period will enable the candidate to perform cutting-edge research at the intersection of economics, medicine, and gerontology to inform health policies towards older adults.